Wavelength Conversion Array for Thermal Management
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Solution Overview
Problem
Laser-phosphor illumination systems face challenges with high energy density leading to thermal damage due to inadequate heat energy removal, and existing methods to distribute thermal energy increase system complexity or diminish optical performance.
Innovation Solution
A wavelength conversion material array on a heatsink, divided into 4 to 12 spots, with a lenslet array to distribute excitation light and collect emitted light, maintaining energy density while improving heat sink effectiveness for better cooling and increased light generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a single large spot of wavelength conversion material is used, then optical collection efficiency is maintained, but heat removal effectiveness is reduced leading to thermal damage
Solution Approach 1:
The single large spot of wavelength conversion material is divided into multiple smaller spots (4 to 12 spots) arranged in an array pattern. This segmentation allows heat to be distributed across multiple contact points with the heat sink, improving heat removal effectiveness while maintaining the same total active area for light conversion.
2Temperature
If the spot size is increased to reduce energy density, then thermal damage is avoided, but optical performance is diminished
Solution Approach 1:
By dividing the total area into multiple smaller spots rather than using one large spot, the energy density is reduced at each individual spot (improving thermal management) while the cumulative active area remains the same (maintaining optical performance). The lenslet array focuses excitation light onto each spot, ensuring efficient light generation across the entire array.
Solution Approach 2:
The solution transitions from a single-dimensional large spot to a two-dimensional array of multiple spots. This dimensional change allows the system to distribute thermal load across multiple spatial locations while maintaining the total light-generating area, effectively decoupling thermal management from optical performance constraints.
3Temperature
If multiple smaller spots are used to improve heat sink effectiveness, then cooling is enhanced, but optical collection efficiency may be reduced
Solution Approach 1:
A lenslet array is introduced as an intermediary optical element that focuses excitation light onto each spot and collects the emitted light. This intermediary component ensures that despite the spots being separated for thermal management, the optical collection efficiency is maintained by directing light from each spot into the collection optics.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for higher energy levels to be incident on the wavelength conversion material, generating more light while balancing optical collection efficiency with heat flow, optimizing both thermal and optical performance.
Implementation Method 1
the wavelength conversion material configured to emit light at a wavelength greater than the excitation wavelength when irradiated by the excitation light
Implementation Method 2
the wavelength conversion material on a heatsink... the heatsink effectiveness can be improved and therefore the phosphor can be more effectively cooled
Data Source
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AI summary
A wavelength conversion material array is provided, including a system comprising: a light source configured to emit excitation light at an excitation wavelength; a heatsink; a wavelength conversion material located on the heatsink, the wavelength conversion material comprising a relative wavelength conversion area of unity divided into an array of spots, a number of the spots in a range of 4 to 12, the wavelength conversion material configured to emit light at a wavelength greater than the excitation wavelength when irradiated by the excitation light; and, an array of lenslets configured to: receive the excitation light from the light source and irradiate each of the spots of the wavelength conversion material with the excitation light, the lenslets in a one-to-one relationship with the number of spots; and collect the light emitted by the wavelength conversion material.